The present invention relates to devices for treating food products and other items, and more particularly to a system for cleaning such devices.
Endless conveyors are frequently employed to transport and handle materials. In the food preparation industry, an endless chain or belt frequently is housed within an enclosure, and arranged in a spiral path whereby a relatively long path is confined within the enclosure. As food items are carried along the path by the conveyor, they are steam cooked, frozen or otherwise treated. The conveyor length and speed determine the treatment duration, to provide continuous as opposed to batch treatment of the food product. This type of device is shown in U.S. Pat. No. 3,834,408 (Thalacker).
In addition to food, this type of conveyor is used to handle other products as well. For example, the Thalacker patent discloses an apparatus for cleaning small electrical parts. The cleaning apparatus carries the parts on an endless chain supported on a helical track. Various nozzles in the apparatus spray a cleaning solvent or solvent condensate onto the parts, which then proceed to a drying region above the nozzles, heated by a spiral steam jacket.
U.S. Pat. No. 4,792,303 (Stewart et al) discloses a bread baking oven with a dual spiral conveyor. A heat distribution system within the oven includes ribbon burners, plenums for receiving gases heated by the burners, and a fan for drawing air through the plenums. From the plenums, heated air is provided to discharge tubes distributed along the spiral conveyor.
When these devices are used in conveying and treating food, cleanliness is of paramount concern. Environments in which food is cooked, frozen, warmed or otherwise treated must be free of harmful bacteria or other contamination, that can spoil or otherwise damage the food, and may lead to serious harm if the affected food is consumed. In ovens, freezers and the like employing spiral belts or chains, devices can be mounted along the path of the belt to spray a cleaning fluid upon the belt as it passes. Further, stationary nozzles can be located throughout the interior of an oven or freezer. However, these approaches have been found less than satisfactory for cleaning the fixed structure that supports the endless belt or other conveyor. Consequently, the support structure must be cleaned by hand, a tedious and time consuming task. Because much of the belt support structure is difficult to see and virtually impossible to reach by hand, manual cleaning runs the risk of falling short of the strict requirements for sanitary handling of food.
Therefore, it is an object of the present invention to provide a food handling and conveying apparatus that is self-cleaning and requires virtually no cleaning by hand.
Another object of the invention is to provide a cleaning system for use in connection with spiral conveyors, that is particularly well suited for cleaning the structure that supports the endless conveyor in its helical path.
A further object is to provide a spraying manifold supported on an endless conveyor and movable along the spiral path traversed by the conveyor, for spraying a cleaning fluid upon the endless conveyor support structure along substantially the entire spiral path.
Yet another object is to provide a manifold of spray nozzles that is quickly and conveniently mounted for use in cleaning a spiral conveyor, then quickly detachable upon completion of the cleaning cycle.